condition mean min max ZT0-3 7.738973 7.738973 7.738973 ZT4-7 9.588103499999999 9.588103499999999 9.588103499999999 ZT8-11 7.720561 7.720561 7.720561 ZT12-15 8.1513205 8.1513205 8.1513205 ZT16-19 11.591922 11.591922 11.591922 ZT20-23 8.681584 8.681584 8.681584